U.S. patent application number 10/754053 was filed with the patent office on 2004-07-22 for apparatus and method for supporting plural codecs.
This patent application is currently assigned to LG Electronics Inc.. Invention is credited to Ji, Salk Mann.
Application Number | 20040140916 10/754053 |
Document ID | / |
Family ID | 32588944 |
Filed Date | 2004-07-22 |
United States Patent
Application |
20040140916 |
Kind Code |
A1 |
Ji, Salk Mann |
July 22, 2004 |
Apparatus and method for supporting plural codecs
Abstract
Different video codecs can be integrated or duplicated functions
of each codec can be shared. According to an apparatus and method
for supporting plural codecs of the present invention, a decoding
process can be performed by analyzing information of a transmitted
bit stream, deciding kind of codec being used by means of a header
analysis unit, connecting through a switching unit to a
corresponding decoder of a decoding unit including plural decoders
or to a corresponding operation block among a plurality of
operation blocks including at least one function.
Inventors: |
Ji, Salk Mann; (Seoul,
KR) |
Correspondence
Address: |
JONATHAN Y. KANG, ESQ.
LEE, HONG, DEGERMAN KANG & SCHMADEKA
14th Floor
801 S. Figueroa Street
Los Angeles
CA
90017
US
|
Assignee: |
LG Electronics Inc.
|
Family ID: |
32588944 |
Appl. No.: |
10/754053 |
Filed: |
January 7, 2004 |
Current U.S.
Class: |
341/50 ;
375/E7.027; 375/E7.093; 375/E7.137; 375/E7.211 |
Current CPC
Class: |
H04N 19/61 20141101;
H04N 19/12 20141101; H04N 19/44 20141101; H04N 19/42 20141101 |
Class at
Publication: |
341/050 |
International
Class: |
H03M 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 8, 2003 |
KR |
1071/2003 |
Claims
What is claimed is:
1. An apparatus for supporting plural codecs, comprising: a header
analysis unit for analyzing input information of a transmitted bit
stream and deciding kind of codec being used; a switching unit,
connected to the header analysis unit, for connecting a
corresponding decoder including a plurality of decoders or to a
corresponding operation block out of plural operation blocks
including at least one function on the basis of the input
information; and a decoding unit for decoding the bit stream by
means of the switched decoder or the operation block.
2. The apparatus according to claim 1, wherein the header analysis
unit analyzes a header of the transmitted compressed bit stream,
decides kind of codec, and generates a switch connection command
corresponding to the decided codec.
3. The apparatus according to claim 1, wherein the switching unit
is connected to the corresponding decoder or each of the operation
blocks.
4. The apparatus according to claim 3, wherein the switching unit
connects the corresponding decoder to each of the operation block,
in response to the switch connection command.
5. The apparatus according to claim 4, wherein the number of
switches to be connected to each of the operation blocks are equal
or less than the number of operation blocks.
6. The apparatus according to claim 1, wherein the decoding unit is
characterized of that each of the operation blocks operated in
respective codecs exists in one board.
7. The apparatus according to claim 6, wherein the decoding unit is
characterized of that each of the operation blocks corresponding to
each codec exists independently in one board.
8. The apparatus according to claim 5, wherein the number of
functions in the operation blocks connected to at least one
switching unit is equal or less than the number of the codecs.
9. The apparatus according to claim 8, wherein the functions of the
operation blocks connected to at least one switching unit can be
integrated in accordance with kind of the codec.
10. A method for supporting plural codecs, comprising the steps of:
analyzing a header of a transmitted compressed bit stream and
deciding kin of codec; and in confirmation to the decided codec,
connecting a switch to a decoding unit including a plurality of
decoders or to an each operation block with own function, and
decoding the bit stream.
11. A method for supporting plural codecs, comprising the steps of:
designating at least one predetermined function capable of
supporting an operation block (function block) in accordance with
kind of codec; in a header analysis unit, analyzing input
information and deciding kind of codec and functions thereof;
switching to a corresponding function in the function block capable
of supporting the decided codec and functions; and decoding the
input information.
12. The method according to claim 11, further comprising the step
of: organizing switching means, in which the number of switching
means is not greater than the number of functions being supported
by each codec.
13. The method according to claim 11, wherein functions of the
operation block are integrated according to a supportable
codec.
14. The method according to claim 12, wherein the number of
functions of the operation block connected to each switching means
is not greater than the number of input codecs.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an apparatus and method for
supporting plural video codecs.
[0003] 2. Discussion of the Background Art
[0004] Communication environment at present and in future is and
will be rapidly changing enough to break distinction between wired
coverage and wireless coverage, or boundaries of nations.
Especially, the third generation communication environment
classified by IMT-2000 shows a current tendency in mobile
communications, providing users with not only image and voice but
also diverse information comprehensively or in real time mode.
[0005] Development in personal communication system also made it
possible for cellular phones or PCS possible to extend services
from a simple voice communication to transmission of mobile text
messages, wireless Internet access, and transmission of moving
pictures that are usually seen in TVs through a personal
communication terminal.
[0006] Such technique is being an essential element in a digital
television system, which processes moving images to digital data,
transmits/receives the digital data in real time mode and displays
on a screen, and in a personal communication terminal adopting
IMT-2000, which transmits moving images in real time mode.
[0007] Traditionally, a portable terminal was devised to
transmit/receive human voices only. However, thanks to the
development of multimedia and digital data processing techniques,
it is now possible to transmit various information including voice
and image.
[0008] Most of all, commercial use of the above technique largely
contributes to a compression technique for moving pictures which
applies special digital processing to analog image signals, e.g.,
quantization and variable length coding, transmits the digitized
signals over a transmit digital channel, and decodes the image
signals at a receiving terminal, thereby transmitting more
information at a higher transmission speed.
[0009] Therefore, unlike in the past, a moving image communication
terminal provides a higher-level service to users by enabling the
users to listen and see real-time moving images and voices.
[0010] FIG. 1 is a schematic block diagram illustrating a
configuration of a related art video decoder.
[0011] Referring to FIG. 1, the video decoder includes a VLD
(variable length decoder) 100, an IQ (inverse quantization) unit
110, an IDCT (inverse discrete cosine transformation) unit 120, a
MC (motion compensation) unit 140, and a mixing unit 130.
[0012] The VLD (variable length decoder) 100 decodes transmitted
compressed bit stream to reconstruct an image therefrom, and
transmits decoded signals to the IQ unit 100.
[0013] Then the IQ unit 110 performs a quantization process to the
transmitted signal from the VLD 100, in an inverse way from a
compression method in an encoder for reconstruction of the
image.
[0014] The IDCT unit 120 performs an inverse discrete cosine
transformation process on the transmitted signal from the IQ unit
110.
[0015] The mixing unit 130 determines whether an image frame of the
transmitted signal from the IDCT unit 120 is an intra mode image
that starts first or an inter mode image with a previous image
frame. If the image frame of the transmitted signal turns out to be
the intra mode image, the mixing unit 130 outputs the image right
away since there is no motion vector therein.
[0016] The MC unit 140 obtains a difference between a motion vector
of an image frame currently being decoded and of a previous image
frame, and compensates the decoded image.
[0017] An operation of the video decoder having the above video
codec will be now explained below.
[0018] An analog image signal undergoes discrete cosine
transformation and quantization in an encoder, and an image frame
signal whose variable length is coded is transmitted to the decoder
in a compressed bit stream.
[0019] The decoder transmits the transmitted bit stream to the VLD
100, and the VLD 100 transforms value and length of the transmitted
bit stream to a two dimensional code.
[0020] Then the VLD 100 transmits the two-dimensional code signal
to the IQ unit 110.
[0021] The IQ unit 110 performs the inverse scan and inverse
quantization to the transmitted signal from the VLD 100, and
transmits the signal to the IDCT unit 120.
[0022] The IDCT unit 120 performs the inverse discrete cosine
transformation to the transmitted signal from the IQ unit 110. Then
the image signal is inputted to the mixing unit 130. The mixing
unit 130 determines whether this image frame to be reconstructed is
an intra mode image that starts first or an inter mode image having
a previous image frame, and if the image frame is of the intra mode
image, outputs the image right away since there is no motion vector
therein. Finally, the MC unit 140 obtains a difference between the
motion vector of the image frame to be decoded and of the previous
image frame, and compensates the decoded image.
[0023] To compare various types of video codecs, some codecs have
the same operation block function and the same embodiment for each
codec, but some codecs have the same function yet a different
embodiment for each codec. For example, IDCT unit 120 performs the
inverse conversion, and its embodiment is equal in MPEG4 and H.263
video codecs. However, although IQ unit 110 performs the inverse
quantization, its embodiment is different in MPEG4 and H.263 video
codecs.
[0024] Therefore, a problem arises that imaging equipment should
have several built-in video codecs to support various kinds of
video, which only increases size and cost of the imaging
equipment.
SUMMARY OF THE INVENTION
[0025] An object of the invention is to solve at least the above
problems and/or disadvantages and to provide at least the
advantages described hereinafter.
[0026] Accordingly, one object of the present invention is to solve
the foregoing problems by providing an apparatus, namely a video
decoder) and method for supporting plural video codecs, in which
the video decoder supports a plurality of video codecs, in which
diverse video codecs can be integrated or one decoder can have
plural function blocks, and the number of functions of the function
block can be integrated according to compatibility among different
codecs, thereby sharing common functions.
[0027] The foregoing object is realized by providing an apparatus
for supporting plural codecs, including: a header analysis unit for
analyzing input information of a transmitted bit stream and
deciding kind of codec being used; a switching unit connected to
the header analysis unit, wherein, on the basis of the input
information, the switching unit is connected to a corresponding
decoder including a plurality of decoders or to a corresponding
operation block out of plural operation blocks including at least
one function; and a decoding unit for decoding the bit stream by
means of the switched decoder or the operation block.
[0028] In an exemplary embodiment of the invention, the header
analysis unit analyzes a header of the transmitted compressed bit
stream, decides kind of codec, and generates a switch connection
command confirming to the decided codec.
[0029] In an exemplary embodiment of the invention, the switching
unit is connected to the corresponding decoder or each of the
operation blocks.
[0030] In an exemplary embodiment of the invention, the switching
unit connects the corresponding decoder to each of the operation
block, in response to the switch connection command.
[0031] In an exemplary embodiment of the invention, the number of
switches to be connected to each of the operation blocks is equal
or less than the number of operation blocks.
[0032] In an exemplary embodiment of the invention, the number of
switches to be connected to each of the operation blocks is equal
or less than the number of operation blocks.
[0033] In an exemplary embodiment of the invention, the decoding
unit is characterized of that each of the operation blocks operated
in respective codecs exists in one board.
[0034] In an exemplary embodiment of the invention, the decoding
unit is characterized of that each of the operation blocks
corresponding to each codec exists independently in one board.
[0035] In an exemplary embodiment of the invention, the number of
functions in the operation blocks connected to at least one
switching unit is equal or less than the number of the codecs.
[0036] In an exemplary embodiment of the invention, the functions
of the operation blocks connected to at least one switching unit
can be integrated in accordance with kind of the codec.
[0037] Another aspect of the invention provides a method for
supporting plural codecs, including the steps of: analyzing a
header of a transmitted compressed bit stream and deciding kin of
codec; and in confirmation to the decided codec, connecting a
switch to a decoding unit including a plurality of decoders or to
an each operation block with own function, and decoding the bit
stream.
[0038] Another aspect of the invention provides a method for
supporting plural codecs, including the steps of: designating at
least one predetermined function capable of supporting an operation
block (function block) in accordance with kind of codec; in a
header analysis unit, analyzing input information and deciding kind
of codec and functions thereof; switching to a corresponding
function in a function block capable of supporting the decided
codec and functions; and decoding the input information.
[0039] According to the apparatus (i.e. the video decoder) and
method for supporting plural video codecs of the present invention,
by pre-analyzing kind of codec used in the input bit stream, it is
possible to decode bit streams of every kind of codec that can be
supported by one single decoder, without loading the decoder.
[0040] Additional advantages, objects, and features of the
invention will be set forth in part in the description which
follows and in part will become apparent to those having ordinary
skill in the art upon examination of the following or may be
learned from practice of the invention. The objects and advantages
of the invention may be realized and attained as particularly
pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] The invention will be described in detail with reference to
the following drawings in which like reference numerals refer to
like elements wherein:
[0042] FIG. 1 is a schematic block diagram illustrating a
configuration of a related art video decoder;
[0043] FIG. 2 is a schematic block diagram illustrating a
configuration of a video decoder for supporting plural codecs in
accordance with a preferred embodiment of the present
invention;
[0044] FIG. 3 is a schematic block diagram illustrating a
configuration of a video decoder for supporting plural codecs in
accordance with another preferred embodiment of the present
invention;
[0045] FIG. 4 is a flow chart describing a method for decoding a
bit stream in accordance with one embodiment of the present
invention; and
[0046] FIG. 5 is a flow chart describing a method for decoding a
bit stream in accordance with another embodiment of the present
invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0047] The following detailed description will present an apparatus
and method for supporting plural codecs according to a preferred
embodiment of the invention in reference to the accompanying
drawings.
[0048] FIG. 2 is a schematic block diagram illustrating a
configuration of a video decoder for supporting plural codecs in
accordance with a preferred embodiment of the present
invention.
[0049] Referring to FIG. 2, the video decoder for supporting plural
codecs includes a header analysis unit 200, a switch 210, and a
decoding unit (220a, 220b, 220n, hereinafter referred to as
220).
[0050] The header analysis unit 200 analyzes a header of a
transmitted compressed bit stream, and determines which decoder
should be used. Therefore, the header analysis unit 200 transmits
to the switch 210 a switch connection command corresponding to kind
of the decoder being determined.
[0051] In response to the transmitted switch connection command
from the header analysis unit 200, the switch 210 connects the
corresponding decoder 220 to the switch.
[0052] The decoder unit 220 includes a first decoder 220a for
supporting H.262 (Codec A decoder for H263), a second decoder 220b
for supporting H.26L, and an n-th decoder 220n for supporting
MPEG4.
[0053] Since each of the decoders has the same configuration with
the one illustrated in FIG. 1, further details thereon will not be
provided here.
[0054] An operation of the video decoder for supporting plural
codecs with the above configuration will be now described.
[0055] When a compressed bit stream is transmitted, the header
analysis unit 200 analyzes the header of the transmitted bit
stream, and decides which decoder should be used.
[0056] That is to say, the header analysis unit 200 selects one of
H.262, H.26L, and MPEG4, on the basis of the header information of
the transmitted bit stream.
[0057] To use the decoder of the corresponding codec to the
decision result, the header analysis unit 200 transmits the switch
connection command to the switch, following the decision
result.
[0058] Then the switch 210, in response to the switch connection
command, connects the corresponding decoder 220. Thus, the
transmitted bit stream to the decoder 220 is transmitted to a VLD
(variable length decoder), and the VLD transforms value and length
of the transmitted bit stream to a two-dimensional code.
[0059] Afterwards, the VLD transmits the two-dimensional coded
signal to an IQ (inverse quantization) unit. The IQ unit performs
the inverse scan to the transmitted signal from the VLD, and
transmits the inversely scanned signal to an IDCT (inverse discrete
cosine transformation) unit.
[0060] The IDCT unit performs the inverse discrete cosine
transformation to the transmitted signal from the IQ unit. In the
IDCT unit, the inverse discrete cosine transformed image is
compensated through a motion vector transmitted from a MC (motion
compensation) unit, and outputted later.
[0061] To compare the above-discussed FIG. 2 with FIG. 3 to be
explained later on, FIG. 2 is characterized of integration of each
decoder, and FIG. 3 is characterized of sharing sharable
function(s) like compatible functions.
[0062] More specifically speaking, FIG. 2 suggests integration and
switching of already applied various kinds of decoders. Even though
it is easy to embody the decoders, when embodied in S/W, their
duplicate functions increase code size. When embodied in H/W, on
the other hand, the hardware area is increased.
[0063] Meanwhile, in FIG. 3, the duplicate functions are taken out
so that they are to be performed only once. Although the complexity
of the decoder seems to be greater, the code size and the hardware
area problems in FIG. 2 are compensated.
[0064] FIG. 3 is a schematic block diagram illustrating a
configuration of a video decoder for supporting plural codecs in
accordance with another preferred embodiment of the present
invention.
[0065] Referring to FIG. 3, the video decoder for supporting plural
codecs includes a header analysis unit 300, a switch unit 310a,
310b, 310c, and 310d (hereinafter they are referred to as 310), a
VLD unit 320a, . . . , 320n (hereinafter they are referred to as
320), an IQ unit 330a, . . . , 330n (hereinafter they are referred
to as 330), an IDCT unit 340a, . . . , 340n (hereinafter they are
referred to as 340), a MC unit 350a, 350b, . . . , 350n
(hereinafter they are referred to as 350), and a mixing unit
360.
[0066] The header analysis unit 300 analyzes a header of a
transmitted compressed bit stream, and decides kind of codec. Then,
corresponding to the kind of codec being decided, the header
analysis unit 300 transmits a switch connection command to the
switch unit 310.
[0067] In response to the transmitted switch connection command
from the header analysis unit 300, the switch unit 310 connects the
switch to a corresponding to operation block. Here, the operation
block includes the VLD 320, the IQ unit 330, the IDCT unit 340, and
the MC unit 350.
[0068] The switch unit 310 includes a first switch 310a, a second
switch 310b, a third switch 310c, and a fourth switch 310d.
[0069] The first switch 310a is connected to the VLD 320
corresponding to the switch connection command, and the second
switch 310b is connected to the IQ unit 330 corresponding to the
switch connection command. The third switch 310c is connected to
the IDCT 340 corresponding to the switch connection command, and
the fourth switch 310d is connected to the MC unit 350
corresponding to the switch connection command.
[0070] For instance, when the switch connection command is a H.263
operation block connection command, the first switch 310a is
connected to a H.263 VLD, the second switch 310b to a H.263 IQ
unit, the third switch 310c to a H.263 IDCT unit, and the fourth
switch 310d to a H.263 MC unit.
[0071] Among other VLD functions of various codecs, the VLD 320
shows different VLDs, e.g., a first VLD 320a, an n-th VLD 320n. For
example, a H.263 VLD and an MPEG4 VLD are different from each
other, and thus, they are embodied respectively.
[0072] The VLD 320 decodes the transmitted compressed bit stream
for reconstruction of an image therefrom, and transmits the decoded
signal to the IQ unit 330.
[0073] Among other inverse quantization functions of various
codecs, the IQ unit 330 shows different IQs, e.g., a first IQ unit
330a, and an n-th IQ unit 330n. For example, a H.263 IQ unit 330
and an MPEG4 IQ unit 330 are different from each other, and thus,
they are embodied respectively.
[0074] The IQ unit 330 performs the quantization to the transmitted
signal from the VLD 320, in an inverse way from a compression
method in an encoder for reconstruction of the image.
[0075] Among other inverse discrete cosine transformation functions
of various codecs, the IDCT unit 340 shows different IDCTs, e.g., a
first IDCT unit 340a, and an n-th IDCT unit 340n. For example, a
H.263 IDCT unit 340 and an MPEG4 IDCT unit 340 are same with each
other so that they can be embodied respectively, or only one of
them can be embodied.
[0076] The IDCT unit 340 performs the inverse discrete cosine
transformation to the transmitted signal from the IQ unit 330.
[0077] Among other motion compensation functions of various codecs,
the MOC unit 350 shows different MC units 350, e.g., a first MC
unit 350a, a second MC unit 350b, and an n-th MC unit 350n.
[0078] For example, a H.263 MC unit 350 and an MPEG4 MC unit 350
are almost same with each other so that they can be combined or
embodied respectively.
[0079] The MC unit 350 compensates the motion vector 350 in the
transmitted image from the IDCT unit 340.
[0080] In the Mixing unit 360, the MC unit 350 compensates the
transmitted signal from the IDCT 340, and the compensated image is
outputted.
[0081] An operation of the video decoder for supporting plural
codecs with the above configuration will be now discussed
below.
[0082] When a compressed bit stream is transmitted, the header
analysis unit 300 analyzes the header of the transmitted bit
stream, and decides which kind of codec to be used. That is, the
header analysis unit 300 decides to which codec out of H.262,
H.26L, and MPEG4 the header of the transmitted bit stream is
compressed.
[0083] Confirming the decision result, the header analysis unit 300
transmits a switch connection command to each switch 310. For
instance, if it turns out that the transmitted bit stream is
compressed in H.263, the header analysis unit 300 transmits a H.263
switch connection command to each switch 310.
[0084] Then the first switch 310a connects the H.263 VLD, the
second switch 310b connects the H.263 IQ unit, the third switch
310c connects the IDCT unit, and the fourth switch 310d connects
the H.263 MC unit, each switch following the H.263 switch
connection command.
[0085] The VLD 320 transforms value and length of the transmitted
bit stream to a two-dimensional code. After that, the VLD 320
transmits the transformed two-dimensional coded signal to the IQ
unit 330.
[0086] In the IQ unit 330, the transmitted signal from the VLD 320
is inversely scanned, and transmitted to the IDCT 340.
[0087] The IDCT unit 340 performs the inverse discrete cosine
transformation to the transmitted signal from the IQ unit 330.
Compensate to the transformed image is a motion vector transmitted
from the MC unit 350, and the compensated image is outputted at the
end.
[0088] FIG. 4 is a flow chart describing a method for decoding a
bit stream in accordance with a preferred embodiment of the present
invention.
[0089] Referring to FIG. 4, the video decoder analyzes the header
of an input bit stream, and decides kind of codec to be applied
(S400). Namely, the video decoder analyzes the header of the input
bit stream to select an appropriate compression method.
[0090] Then the video decoder connects the switch to a decoder with
the decided codec or to an operation block (S402), and decodes the
bit stream (S404).
[0091] FIG. 5 is a flow chart describing a method for decoding a
bit stream in accordance with another embodiment of the present
invention.
[0092] At least one of predetermined functions that can support an
operation block (refer to 320, 330, 340, and 350 in FIG. 3), which
is a function block, is designated in accordance with kind of codec
(H263, H26L, MPEG and so on) (S500).
[0093] In other words, a user refers to a data book or a codec SPEC
and finds out which codec supports which codec.
[0094] A switching means is organized for each function, that is,
the number of the switching means is not greater than the number of
functions supported by each codec (S502).
[0095] The header analysis unit analyzes input information and
finds out each of the codecs and functions thereof, and connects
the switch to a corresponding function in a given function block
that can support the decided codec and function thereof (S504).
[0096] The input information is decoded (S506).
[0097] To elaborate and understand the decoding method described in
FIG. 5, it will be useful to know each of codecs H, 263, H.26L,
MPEG-1, MPEG-2, and MPEG-4 has the VLD, the IQ, the IDCT, and the
MC.
[0098] Although not standard, there are other kinds of image
decoders, including DivX, RealVideo, WindowsMediaVideo, etc. Each
of these image decoders also has the VLD, the IQ, the IDCT, and the
MC.
[0099] However, suppose that an MPEG-4 VLD function, for example,
covers a H.263 VLD, an MPEG-1 VLD, and an MPEG-2 VLD. In such case,
it will be unnecessary to use another VLD in a different codec, as
long as there is an MPEG-4 compatible VLC.
[0100] Similarly, an MPEG-4 IQ can support an MPEG-2 IQ and a H.263
IQ. Needless to say, an MPEG-4 compatible IQ can cover the other
two.
[0101] To make a conclusion, according to the embodiment
illustrated in FIG. 2, total 8 function blocks, two for each of the
VLD, the IQ, the IDCT, and the MC, to manufacture a decoder that
can support both the MPEG-4 and H.263 codecs (or standards) at the
same time. In the meantime, according to the embodiment illustrated
in FIG. 3, since the MPEG-4 codec covers the H.263 codec, only 4
function blocks, one for each of the VLD, the IQ, the IDCT, and the
MC, are needed to manufacture the same type of decoder.
[0102] Therefore, the embodiment of FIG. 3 is suggesting that since
most of image decoders have the same configuration and function
blocks thereof are basically same, the image decoders can be
decomposed to function blocks and put together again.
[0103] In conclusion, according to the apparatus (i.e. the video
decoder) and method for supporting plural video codecs of the
present invention, by pre-analyzing kind of codec used in the input
bit stream, it is possible to decode bit streams of every kind of
codec that can be supported by one single decoder, without loading
the decoder.
[0104] Also, according to the present invention, compatible or
sharable functions can be shared to perform the decoding.
[0105] One embodiment of the present invention introduced an idea
of integrating and switching various types of decoders to improve
convenience of usage, and another embodiment of the present
invention suggested that duplicated functions can be shared to
reduce code size and hardware area.
[0106] While the invention has been shown and described with
reference to certain preferred embodiments thereof, it will be
understood by those skilled in the art that various changes in form
and details may be made therein without departing from the spirit
and scope of the invention as defined by the appended claims.
[0107] The foregoing embodiments and advantages are merely
exemplary and are not to be construed as limiting the present
invention. The present teaching can be readily applied to other
types of apparatuses. The description of the present invention is
intended to be illustrative, and not to limit the scope of the
claims. Many alternatives, modifications, and variations will be
apparent to those skilled in the art. In the claims,
means-plus-function clauses are intended to cover the structures
described herein as performing the recited function and not only
structural equivalents but also equivalent structures.
* * * * *